Maine harness racing has received $122 million in slot machine revenue in the last 12 years, money aimed at invigorating a struggling industry. Instead, the millions have merely slowed what appears to be its inevitable decline.

It’s either time for the racing industry to show it has a plan for growth that goes beyond casino revenue, or for the Legislature to repurpose the money in a way that honors its original intent — supporting agriculture.

The casino revenue comes as a result of the 2003 statewide referendum that allowed for slot machines in Bangor, and since 2005 has given the industry an average of $9.3 million a year, according to a report from Pine Tree Watch.

The funding was designed to raise purses in order to attract better racing to Maine. Better racing, the thinking went, would attract more spectators and gamblers, supporting the owners, trainers and farmers who make up the industry.

But the Legislature asked for no accounting on how the money was spent, and the industry has offered none. While some of the funding initially was invested in the racetracks in Bangor and Scarborough, it has more recently been used to simply cover operating costs. Scarborough Downs, the center of harness racing in Maine, would have run $1.3 million in the red in 2013 were it not for slot machine revenue.

Sure, the subsidy provided by the casino revenue has kept those tracks open and the industry operating. It’s supported trainers, grain and hay suppliers, and veterenarians, and kept acres of land open for farming. But for how long?

The property containing Scarborough Downs, prime commercial real estate, is now under contract with a developer, with the future of its track very much in doubt. Since 2003, Pine Tree Watch found, betting statewide has dropped 57 percent, licensed horse owners 40 percent, and the number of mares bred 44 percent. Harness racing gambling revenue is a small fraction of what it was 30 years ago. Regulators have said that the industry is on the “brink of viability.”

If the harness racing industry has a plan for reversing this slide, it isn’t saying, except to argue for continued casino funding, and more if another gambling facility is built in southern Maine. Advocates say they are entitled to the casino funding because the industry played a key role in raising support for the gambling referendum.

That’s true, but much of that support was directed at maintaining agricultural land and jobs. There are other ways to do that with the money that now goes to harness racing each year — it could be used to make investments in local food and farming that would pay off for years.

Instead, it is going to a dying industry that has shown little hope of turning itself around. Millions of dollars haven’t helped yet, and there is no indication that more will turn the tide. Unless the harness racing industry can change that, the money can be spent better elsewhere, and it should be.